"Dude" sounds
At the main menu, press R2, R1, L2, R2, Square, Triangle, L1, R1. If you entered the code correctly, you will hear a sound.
All Cars and Tracks
Go to the password screen (from the main menu) and enter PWDTST to access all cars and tracks.
Flat shaded graphics
At the main menu, press L1, R1, L2, R2, L1, R1, L2, R2. If you entered the code correctly, you will hear a sound.
Infinite turbos
At the main menu, press R2, L1, Square, Triangle, R1, L2, L1, R2. If you entered the code correctly, you will hear a sound.
Large tires
At the main menu, press Square, Triangle, Square, Triangle, R1(2), L2(2). If you entered the code correctly, you will hear a sound.
Small cars
At the main menu, press Square, R2, L2, Triangle(2), L2, R2, Square. If you entered the code correctly, you will hear a sound.
TowJam car
At the main menu, press Square, Triangle, L1, R1, L2, R2, Square, Triangle. If you entered the code correctly, you will hear a sound.